The Bonin flying fox (オガサワラオオコウモリ) is endemic to Japan and has been found in a few islands of Ogasawara (known as the Bonin Islands in English). The Bonin flying fox is called Ogasawara Ookōmori in Japanese. Oo means “big” and kōmori means a “bat.” Needless to say, an ookōmori is bigger than a regular kōmori (its body is about 9 inches long), but also ookōmori eat fruits whereas kōmori normally eat small insects. Also the ookōmori’s eyes are fully functional unlike those of an ordinary kōmori. Therefore, an ookōmori is normally diurnal where a kōmori is normally nocturnal. Strangely, some Bonin flying foxes are diurnal and others are nocturnal depending on the island where they live. Since 1969 Bonin flying foxes have been designated as natural treasures of Japan.
